Can body for sanitary cans



May 30, 1933. J. cOYLE CAN BODY FOR SANITARY CANS Filed July 26, 1932 2 Sheets-Sheet 1 May 30, 1933. J. COYLE CAN BODY FOR SANITARY CANS Filed July 26 1952 2 Sheets-Sheet Marx fa /2 0110 2 /64). Z],

56 blank with the hooks bent and Patented May 30, 1933 UNITED STATES PATENT osFicE 1'1 JOHN COYLE, 0F BALTIMORE, MARYLAND, ASSIGNOR'TO. CONTINENTAL GAN INC., OF' NEW YORK, N. Y., A CORPORATION OF NEW YORK CAN BODY FOR SANITARY CANS Application filed July 26,

The invention relates to new and useful improvements in a can body for a sanitary can, that is, a can wherein end closures are joined to the body by a double seam.

Anobject of the invention is to provide a construction of can body having a lock and lap side seam wherein the solder bond joining the lap sections is extended at each side of the interlocked portions of the side seam, and the lap sections are so shaped that the solder bond is relieved from all strain during the initial turning of the flange, and wherein the strain on the solder bond during the completion of the formation of the flange is a shifting strain.

A further object of the invention is to provide a can body of the above type wherein the outer edges of the lapping portions are space is provided for the expansion of the lapping portions rolled into the double seam, so that the double seam throughout its entire length may be uniform in cross section.

In thedrawings: Figure 1 is a view showing more or less diagrammatically, and on a small scale, a blank which has been provided with slits and shaped to as to form the improved can body Fig. 2 is a similar view of a portion of the positioned for interlocking;

Fig. 3 is a View of one end of the can body embodying the improvements, with the s1de i, seam completed and flanged;

35 Fig. i is an enlarged View of a portion of one end'of the side seam;

Fig. 5 is a vertical sectional view of a portion of one end of the flanged can body;

Fig. 6 is a sectional View on the line 6-6 of Fig. 3;.

Fig. 7 is a sectional view on the line 7-7, of Fig. 3;

Fig. 8 is a view showing diagrammatically a portion of a can body with an end closure 45 applied thereto preparatory to double seam- Fig. 9 is a side view of a portion of a can body with the closure end secured thereto by double seaming; 1 Fig; 10 is a sectional view on the line 10-10 so shaped that during double seaming, a

1932. Serial No. 624,859.

of Fig. 9, through the can body afterthe first seaming operation has rolled the closure end which is particularly adapted for the form-- ing of the so-called sanitary can, that is,- a can wherein the end closuresare secured to the flanged body by double seaming. It is a common expedient to form a; can body for such a can by uniting the ends of the body blank by a lock and lap side seam. Throughout the greater portion of the side seam,

the edge portions are. interlocked. At the ends of the side seam, however, the metal parts are merely lapped so that they maybe turned into a flange and the endsv secured thereto by double seaming. This lock and lap seam is bonded by solder which joins the lapping portions at the ends ofthe side seam,

as well as the interlocked portions. 'A'gre'at deal of difliculty has been experienced in the forming of the flange without rupturing the solder bond uniting the lapping portions of the side seam. Difliculty, has also been ex perienced in forming a double seam without rupturing this solder bond. The present invention has particularly to do with the shaping of the metal parts forming the lap sections of the side seam. The body blank is slit or notched so as to form hooks, with a portion of the body blank at each end there'- of extending beyond the formed hook, so that when the hooks are interlocked at the ends of the body blank,the lapping portions of the side seam will extend for a distance at each side of the interlocked portion of the side seam. This increases the width of the solder bond at the lap section of the side seam.- While it is desirable to extend the width of the solder bond'immed'iately at the ping sections of the side seam are cut away point 10 to the point 12.

and curved so that they intersect at a point well back from a line containing the extreme edges of the body blank, but within the limits of the flange to be formed on the can body. This extending of the lapping portions and the curving and shaping of the outer edgesthereofproduces a side seam which is very strong at the lapping sections which is uniform in cross section through-.

out may be produced. 7

Referring more in detail to the drawings, the can body is formed from a blank indicated at 1, The blank is providedwith slits 2, 2 at one end thereof, and slits 3, 3 at the other end thereof. Between the slits 2, 2 the metal is turned into a hook 4, and between the slits 33 the metal is turned into a hook 5. The hook 4 faces in one direction and the hook 5 in the other, so that when the blank i s-bent into a cylindrical shape, these hooks may be interlocked, and this willform the interlocked portion of the side seam 6. In Fig. 6 of the drawings, a sectional View is shown through the side seam 6, and showing the interlocked hooks 4 and 5. At the ends of the hook 4 are the lapping portions 7 ,7 of the side seam, and at the ends of the hook 5 are the lapping portions 8, 8v thereof. Whenv the hooks are interlocked, theportion 7 will overlie or lap 011 to the portion 8, as shown in Figures 3, 4 and 7. The portion 7 extends to one side of the interlocked portion of the side seam a distance substantially equal to the length of the hook 4. The portion 8 extends to theother side of the side seam at a similar distance. The metal parts atthe ends of the side seam overlap from the point 9 to-the point 10. The two lapping portions at the end of the side seam are similar in construction, and the description of one will answer for the other. The edge of the lapping portion 7 is curved from this point 9 to'the point 11. The edge of the lapping portion 8 is curved from the edges of the lapping portions intersect at the point 13. The line of the edge of the can body is indicated at y Q in Fig. l, and it is noted that the edges of the lapping portions curve away from this line gradually until the points 9 and 10 are reached.

After the body blank has been shapedand the hook portions interlocked and bumped together, then solder is applied throughout the entire length of the side seam, .whiclr These curved,

tion ofthe can body into the flange 1%. This is a progressive turning'action which produces the flange. The die contacts with the can body along the line g g Fig. 4, and the metal will be radually turned and expands to produce the flange, said metal. being turned outwardly substantially to the line w-m in Fig. l. During t-his turning of the flange there is a single thickness of-inetal which is being turned until the'point. 18 is reached, so that duringthe initial turning of the. flange, there is little .01 no strain on the solder bond joining the lapping portions -7 and 8. hat-ever strain may be imposed on the solder bond is a pulling strain distributed over the entire solder bond. strain on the metal forming the flangeis not localized, but distributed, andtherefore, all

likelihood of fracturing the metal is avoided. Thestrain alongthe curved edge gradually approaches the intersecting pointl3 and continues to shift along said curved edge until the flange is completed. The metal in the initially formed portionof the flange is expanded to a much greater extent than that, portion of the flangewhere it joins the can body. Not only is'a comparatively small portion of the lapping metal sections forced outward into the flange, but the strains thereon are shifting strains and well within the elasticity of the metal, thus reducing the strain on thesolderbond so that it is'not ruptured. I

The solder bond at the lapping portion is indicated by the broken shade lines in Fig. 4. It will be noted from Figs. 3. and 4 that the lapping portions of the side seam have been constructed so as to extend the solder bond; in that portion where the metal is not turned into the flange, and at that portion which is turned into the flange, the strain minimum.

After the body flanged, thenthe closing end indicated at isplaced thereon, and this closing end has a portion thereof extending across and around the edge of the flange of the can body. A sealing material is placed in the channel thus formed in the closing end. The

on the solder bond has been reduced to a end is chucked on the can body, and either,

the body and end with the chuck are rotated,

or the seaming rolls are caused to travel about: the can body for. rolling the can end and'the body flange into a double seam. Figure 10 is a sectional View through the seam-at the end of the firstseaming' opera- Likewise, the

has been formed and tion, and at one side of the double seam there is only a single thickness of metal in the flange. Figure 11 is a similar View centrally of the side seam and through a double thickness of the metal in the flange. It will be noted that there is a greater space or void between the end 16 of the flange and the lower part 17 of the rolled cover at the side seam where there are two thicknesses of metal. This is due to the cutting away of the overlapping sections as described above. In Figure 12 of the drawings, there is shown a section through the double seam after the completion of the second operation, and on a line centrally through the side seam. The pressure of the second operating roll causes the metal in the overlapped portions of the body to flow, and this will fill the space or void, but will not contact with the rolled portion 7 of the cover so as to enlarge the double seam where it crosses the side seam. In other words, the double seam is substantially uniform in cross section. If, due to variations in the thickness of metal, there are still voids in this region where the lapped sections are cut away, the sealing material will be caused to flow into and fill said voids, and a double seam is formed not only of uniform dimensions throughout, but wherein there is a tight seal throughout.

During the seaming operation, the metal parts are gradually rolled to their final position, as shown in Figures 10, 11 and 12. The pressureof the seaming roll first contacts with the curved edge of the lapping portions at a distance back from the center of the side seam. The pressure along the edge gradually shifts along the curved edge all the way to the finishing of the double seam. The maximum rolling or bending action in the metal is at the outer edge thereof where there is a single thickness of meta-L The parts of the lapped portions of the side seam which are rolled into the double seam are caused to flow to a less extent, and the strain is well within the elasticity of the metal. This, together with the shifting point of application of maximum strain distributes the strain on the solder bond so that there is no likelihood of rupturing the solder bond during seaming.

From the above it will be apparent that by the construction of the lapping portions of the side seam described, there is little liability of disturbing the solder bond or causing a leak during double seaming.

It is obvious that minor changes in the shaping of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is

1. A can body consisting of a metal blank having the ends thereof joined to form a lock and lap side seam and the end portions of the formed body flanged, the lapping portions at the ends of the side seam being extended each side of the locking portions and the outer edges of said lapping portions being gradually curved away from a line containing the edge of the blank and intersecting at a distance from said line and within the limits of the flange whereby the strain on the solder bond joining the lapping sections is relieved during the initial turning of the flange and is a gradual shifting strain during the completing of the turning of the flange.

, 2. A can body consisting of a metal blank having the ends thereof joined to form a lock and lap side seam and the end portions of the formed body flanged, the lapping portions at the ends of the side seam being extended at each side of the locking portions a distance substantially equal to the length of the interlocking hooks, and the outer edge of said lapping portions being gradually curved away from a line containing the edge of the blank, each curved edge beginning at a point at one side of the maximum lapping region extending to the other side thereof, and intersecting at a distance from said line within the limits of the flange, whereby the strain on the solder bond during flanging and during double seaming is reduced to a minimum and is a gradual shifting strain.

In testimony whereof, I affix my signature.

JOHN COYLE. 

